Previous iterations were about the size of a biscuit, 10 times larger than the new models, and sat in a pocket of flesh near the collarbone, connecting to the heart with a wire.

The new technology, trialled in Australia in two very similar forms from companies Medtronic and St Jude since 2014, eliminated both the wire and the pocket, the two major causes of complications.

"At a stroke we get rid of potential problems with the lead because there isn't one," Princess Alexandra Hospital director of Cardiac Electrophysiology Dr John Hill said.

"And there's no pocket in the chest to be associated with risk of infection there or shoulder discomfort or cosmetic issues, so that's very exciting for us."

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The implementation surgery was simpler too, requiring just a small incision in the groin for a surgeon to steer the device through the body and attach it to the wall of the heart.

"Overall I think this is the most exciting development in pacemaker technology in nearly six decades of pacemaker implantation in humans," Dr Hill said

In December 2014, Sunshine Coast grandmother Madeleine Johnston was one of the first in the country to have the tiny device, little bigger than a painkiller capsule, implanted.

The 74-year-old community theatre enthusiast had a low and erratic heartbeat before having the pacemaker fitted.

"It's a marvellous, wonderful miracle and the very day after I had it done I felt terrific," she said.

"It came to me almost (through) serendipity.

"My cardiologist went to a seminar, met Dr Hill, they talked about this wonderful device and he said 'I think she might be a candidate for it".

"I felt like a new person."

The PA had implanted 14 pacemakers in patients and a handful of other surgeries had been performed in other hospitals including Prince Charles in Brisbane's north.

Dr Hill said clinical trials showed the devices performed just as effectively, if not more so, than existing products.

It's only limitation, he said, aside from continuing to set off airport security detectors, was the device's inability to control more than one of the heart's four chambers.

It was estimated about 10 per cent of the roughly 17,500 Australians fitted with pacemakers each year could benefit from the radical improvement when it was approved by the Therapeutic Goods Administration.

He said most pacemaker patients needed at least two chambers stimulated but his hospital was working with the makers towards expanding the capabilities "within a couple of years".